For starters, it's just 30MB. Thanks to its minuscule size, you can boot the distro straight off the web into RAM. This is a wonderful way to regularly check out the current development version.

Due to its size, Slitaz takes an unconventional approach to apps. Traditional apps are replaced with lightweight equivalents, such as the Midori web browser. Slitaz also assumes you have a decent connection to the internet, which it relies on to fetch apps as you need them. For example, there's a basic text editor, but click Write Documents and the distro fetches and installs AbiWord.

You'll find lots of custom tools and apps here. There's BurnBox for writing DVDs, NetBox and WifiBox to set up wired and wireless connections, and Tazlito to remaster the Slitaz live CD. Slitaz can be installed to a hard disk or USB mass storage device. To generate a live USB system, you can use the Tazusb tool. You can install new packages via the mirrors, a DVD, or from a USB storage device.

Package management from the command line is handled via custom manager TazPkg. There's also Tazwok to configure and compile a package from source.

Zenwalk

Care for a blast from the past? Then carve out a partition for Zenwalk. This distro is optimised for performance on older hardware and is available in various flavours.

The standard edition has Xfce, although there are versions that offer Gnome and Openbox desktops as well. Zenwalk used to be based on Slackware and is still compatible with its binary packages. Now, however, the distro uses its own Netpkg package manager, which adds dependency resolution capabilities to TGZ packages.

Instead of running the vanilla version of the Firefox browser, the distro uses GNU IceCat with plugins for Flash, QuickTime, DivX and more. There's no Java Runtime Environment, but it can be easily installed via Netpkg.

Zenwalk's installer brings back fond memories of the Ncurses-based Slackware installer. It uses cfdisk for partitioning, and includes an auto-install option that creates a dedicated partition and installs packages.

Zenwalk is also one of the few mainstream distros to still use the Lilo bootloader, and displays the GNU GPL before booting the desktop. Classic!

When you first boot into the distro, you're required to set up a password for root, after which you can add or view users and groups. There's good news if you like to be in command of your installations, too: Zenwalk gives you control over the groups a user belongs to.

More advanced users will also appreciate the convenience of the included kernel module configurator, kernelconfig, which enables you to select which kernel modules to load.

CrunchBang Linux

Plenty of distros that attempt to cater for older hardware just switch Gnome or KDE for a lightweight desktop environment and call the job done, which is why they aren't as actively developed as CrunchBang Linux.

CrunchBang developers go the extra mile to ensure you don't just have a distro for older hardware, but a nippy one at that. The live CD boots quickly to a minimal desktop with a right-click menu, and application launch shortcut keys are displayed on the desktop.

The latest stable release is based on Ubuntu, but subsequent versions will be based on Debian Squeeze sources.

Besides the Openbox and Xfce desktops, the developers have painstakingly chosen lightweight alternatives to regular desktop apps, such as Claws Mail, gPodder podcast grabber, AbiWord, Gnumeric and their ilk. There are also lots of terminal-based apps, such as Rtorrent, Vim, Mutt for email and the Irssi IRC client.

The distro also includes links to online tools such as Colour Hunter to create and find colour palettes from images, Vector Magic to convert bitmaps to vector art, and a tool to create favicons from pics.

There's no lack of multimedia apps either, including VLC, Rythmbox and libraries to play all types of media files. Kino and Pitivi video editors are on board too, as are RecordMyDesktop for creating screencasts, WinFF video converter and more.

You also get the option to enable compositing, set window transparency, choose wallpapers and select appearance settings. The developers have made smart use of the menu as well. Instead of having to hunt for config files for various components, they're all neatly placed inside it. There are links to lots of documentation too.

Puppy Linux

Puppy Linux is great. It isn't just featherweight in size, it's also packed with custom tools for tweaking almost anything about it you can think of. The minuscule live distro loads completely into the RAM and brings up a welcome screen on the lightweight JWM window manager.

Puppy detects graphics cards and recommends the driver to download and use. In addition to ATI and Nvidia cards, Puppy is also aware of the VirtualBox graphics card. You can download and activate a driver in just a couple of clicks. It's also got NdisWrapper to work with wireless cards that have Windows-only binary drivers.

Those custom tools we mentioned earlier can help with configuring the X server, sound, printers, firewall, backup, mirroring and file encryption. Most tools have a wizard to guide newer users through the setup before using the app too.

Just because it's 130MB doesn't mean you're short of apps either. Besides the usual slew, there's an alarm clock, a unit converter and scientific calculator, plus tools to stream audio, grab podcasts and much more.

While you're at it, make sure you check out the Quickpet utility, which gives you access to oft-used apps such as Wine, Google Earth, Pwidgets, Firefox and Java. This is in addition to the tons of apps in the fully fledged Puppy Package Manager.

By default, the puppylucid repo is enabled, but you can enable and pull in packages from others too, such as ubuntu-luciduniverse and ubuntu-lucid. Puppy can be installed to a variety of removable media, as well as inside a Windows partition. There's detailed documentation on the website, and help is just a forum post away.